MORPHOLOGY AND EVOLUTION
The glands of the tongue belong to the serous and mucous types; but ilan and the Orang differ from all other Primates in possessing the apical gland of Xuhn. The latter is a part of the basal mucous glands which has become separated from the main mass.
The pharynx is as in ilan, Faucial and pharyngeal
FIG. 39.—The tongue of the Orang-Outan. A., upper surface; B., inferior surface (the arrows point to the position of the submaxillary glands); C.j side view of tongue,
tonsils are both present, and are nourished from the vascular circle formed by the branches of the ascending pharyngeal artery. The former is covered by fenestrated mucous membrane. Although lingual, faucial and pharyngeal tonsils are present I was unable to detect Waldeyer's lymphatic ring. Seesel's pocket is absent-The constrictor muscles are as in Man. The sinus of